羟基氯醋改性聚氨酯预聚体合成反应动力学研究

The studies on reaction kinetic of polyurethane prepolymerization modified by alcoholized poly(vinyl chloride-vinyl acetate)

采用化学分析方法研究了羟基氯醋树脂微粉存在下的聚醚N-220、蓖麻油等聚醚多元醇混合物与甲苯二异氰酸酯(TDI-80)的预聚合反应动力学,获得了聚氨酯预聚体合成反应动力学参数及反应表观速率常数表达式k=0.049exp(-23.95/RT),并通过反应初期的实验数据对反应级数进行了验证。结果表明,在该体系下的预聚体合成反应中,氨酯化反应的表观速率常数随反应温度的升高而增大,合成反应以氨酯化反应为主,总反应级数为1.74～1.88,为近二级反应。该合成反应机理具有一定的复杂性。实验结果对相关聚氨酯弹性体预聚物合成及改性反应具有一定的理论价值和指导意义。

The urethane reaction kinetics of polyurethane prepolymerization was researched by using toluene diisocynate （ TDI-80）, polyether-N220, castor oil, and alcoholized PVC-VAc which will make polyurethane possess good dielectric properties for raw material. Furthermore, the urethane reaction kinetics parameter, reaction apparent rate constant equation [ k = 0.049exp （-23.95/RT） ] and reaction order of polyurethane prepolymerization were obtained. The results show that the reaction apparent rate constant of urethane reaction kinetics increases with temperature. The urethane reaction is a main reaction in the whole process. Approximate second order of reaction kinetic model is proved by the order deduction. The overall reaction order is about 1.74 ~ 1.88. This prepolymerization is a complicated reaction. And this paper can guide the interrelated research of reaction kinetic of polyurethane prepolymerization.